1. Field of the Invention
This invention relates generally to an image sensor with electronic shuttering and, more particularly, to a semiconductor image sensor in which signal charge may be selectively isolated to provide electronic shuttering.
2. Description of the Prior Art
Electronic still image cameras embodying solid state image sensing arrays are now well known in the art. Such cameras are operated in a manner similar to conventional cameras in that the camera user first frames and composes a scene to be recorded and then actuates a button on the camera to commence an exposure time interval during which scene light is integrated by an image sensing array. The commencement and termination of such exposure intervals are generally controlled by conventional mechanical shutter mechanisms that initially move out of a scene light blocking position with respect to the image sensing array to commence the exposure interval and after a select exposure time period move back into the scene light blocking position with respect to the image sensing array to terminate the exposure interval. Such mechanical shutter mechanisms add undue cost and complexity to electronic imaging cameras. It is, therefore, desirable to do away with such mechanical shutters by electronically shuttering the image sensing array so as to electronically control the time duration which image scene light is integrated. Although image sensing arrays may be electronically actuated and deactuated to control, respectively, the initiation and termination of charge integration, charge leakage during the off period generally degrades the image previously captured during the exposure interval.
Therefore, it is a primary object of this invention to provide a solid state image sensor for an electronic still image camera that may be used without a mechanical shutter.
It is a further object of this invention to provide a solid state image sensor that may be electronically shuttered by effectively isolating the signal charges integrated by each light sensing element of the array.
Other objects of the invention will be, in part, obvious and will, in part, appear hereinafter. The invention accordingly comprises a mechanism and system possessing the construction, combination of elements, and arrangement of parts which are exemplified in the following detailed disclosure.